Improved dry-dock indicator



P. F. CAMPBELL.

DryDock Indicator.

Patented JuIy 31, 1866.

IIIIIII UII III II II '3 I [HI I I II III 0 IIIIIIW Ji UNITED STATES PETER F. CAMPBELL, OF JERSEY CITY, NEW JERSEY.

IMPROVED DRY-DOCK INDICATOR.

Specification forming part of Letters Patent No. 56,702, dated July 31, 1866.

To all whom it may concern:

Be it known that I, PETER F. CAMPBELL, of Jersey City, in the county of Hudson and State of New Jersey, have invented and made a certain new and useful Improvement in Indicators for the Sections or Compartments of Dry-Docks; and I do hereby declare the following to be a full, clear, and exact description of the said invention, reference being had to the annexed drawings, making part of this specification, wherein-- Figure 1 is a section showing one side of a dock with my indicator attached; and Fig. 2 is an elevation of the indicator, the dock bein g partially in section.

Similar letters denote the same parts.

In dry-docks for vessels it is usual to allow water to flow into the hollow sections or compartments, in order that the dock may be sunk for the delivery of one vessel and the reception of another. In raising the dock and vessel, the compartments or sections are pumped out, and in so doing it frequently happens that one section is pumped out more quickly than another, in consequence of local obstruction to the pumps. The consequence is that undue strain comes upon the dock and frequently upon the vessel, in consequence of not resting upon an even keel, and sometimes the dock itself is injured by the timbers that connect.

the sections being broken.

The object of my invention. is to indicate the height of Water in each ofthe compartments or sections of a dry-dock, so that the overseer or foreman can tell, by inspection, Whether the vessel is being lifted properly and each part of the dock performing the duty required of it.

My invention consists in combining with the section or' compartment of a dry-dock a float and indicating apparatus, by which the height of water within the section or'compartment can be indicated and determined by inspection.

In the drawings, a represents one of the sections or compartments of a dry-dock; I), the central beam or bearer for the vessels keel; c, the elevated side of the dock. These parts are to be of any usual or desired construction.

dis a drum, over which the belt or chain It passes to the float cl, and said belt or chain passes below one or two rollers, 0, according to the size of the drum 6, so that the belt or chain hangs vertically, and is guided properly as motion is given to the belt or chain and the drum 6 by the float d, as the water rises or falls in the compartment a. From the drum i mo tion is communicated, through the pinion 0 and Wheelf, to the hand l, in front of the dial 9.

The dial 9 is to be divided off so as to indicate in feet and inches or other notation the height of water in the compartment a,and the chain or belt f may also have figures marked thereon, as seen in Fig. 2, so that the height of water may be inspected when the person is not in front of the dial.

A counterpoise, m, may be attached to the chain or belt f, to increase the friction of the belt or chain f upon the pulley or drum 1', so

that it will not be liable to slip as the float is rising.

The size of the drum 6 may be varied as required. It must, however, be in proportion,

- CHAS. H. Sll/HTH. 

